The economy expanded less than expected in the third quarter on slower consumption and public spending, but early signs of an export recovery have raised hopes for stronger growth ahead.
The economy grew a seasonally adjusted 0.6% in July-September from the prior three months, the National Economic and Social Development Board (NESDB) said on Monday.
The pace slightly lagged the revised 0.7% in the second quarter, and the 0.7% forecast in a Reuters poll.
From a year earlier, growth was 3.2%, down from 3.5% in the second quarter and against the poll's median of 3.4% growth for July-September.
Annual growth in public investment and household spending slowed in the September quarter while private investment contracted, the NESDB statement said.
The government estimated the economy would grow 3.2% in 2016, with exports being flat. Previously it forecast 3.0-3.5% growth for this year, while exports were projected to fall 1.9%.
The NESDB predicted 2017 GDP would grow 3.0-4.0% and exports expand 2.4%. Last year's growth was 2.8%
Tourism has been a rare bright spot but it may slow on cutbacks in entertainment since the passing of King Bhumibol Adulyadej on Oct 13. The government declared official mourning for a year.
A crackdown on so-called zero-dollar tours has reduced the number of visitors from China, Thailand's biggest source.
The economy has lagged behind regional peers and may fall prey to capital outflows on the prospect of higher US interest rates.
Foreign investors have sold a net of about 99.4 billion baht of Thai bonds and stocks since Nov 9, the day after the US presidential election.
However, Deputy Prime Minister Somkid Jatusripitak said on Friday outflows were not a worry and a weak baht was good for exports, which have contracted in each of the past three years. If needed, the finance ministry was ready to introduce additional steps, he said.